/*
 * TWL6030 GPADC module driver
 *
 * Copyright (C) 2009-2013 Texas Instruments Inc.
 * Nishant Kamat <nskamat@ti.com>
 * Balaji T K <balajitk@ti.com>
 * Graeme Gregory <gg@slimlogic.co.uk>
 * Girish S Ghongdemath <girishsg@ti.com>
 * Ambresh K <ambresh@ti.com>
 * Oleksandr Kozaruk <oleksandr.kozaruk@ti.com
 *
 * Based on twl4030-madc.c
 * Copyright (C) 2008 Nokia Corporation
 * Mikko Ylinen <mikko.k.ylinen@nokia.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of_platform.h>
#include <linux/i2c/twl.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define DRIVER_NAME             "twl6030_gpadc"

/*
 * twl6030 per TRM has 17 channels, and twl6032 has 19 channels
 * 2 test network channels are not used,
 * 2 die temperature channels are not used either, as it is not
 * defined how to convert ADC value to temperature
 */
#define TWL6030_GPADC_USED_CHANNELS             13
#define TWL6030_GPADC_MAX_CHANNELS              15
#define TWL6032_GPADC_USED_CHANNELS             15
#define TWL6032_GPADC_MAX_CHANNELS              19
#define TWL6030_GPADC_NUM_TRIM_REGS             16

#define TWL6030_GPADC_CTRL_P1                   0x05

#define TWL6032_GPADC_GPSELECT_ISB              0x07
#define TWL6032_GPADC_CTRL_P1                   0x08

#define TWL6032_GPADC_GPCH0_LSB                 0x0d
#define TWL6032_GPADC_GPCH0_MSB                 0x0e

#define TWL6030_GPADC_CTRL_P1_SP1               BIT(3)

#define TWL6030_GPADC_GPCH0_LSB                 (0x29)

#define TWL6030_GPADC_RT_SW1_EOC_MASK           BIT(5)

#define TWL6030_GPADC_TRIM1                     0xCD

#define TWL6030_REG_TOGGLE1                     0x90
#define TWL6030_GPADCS                          BIT(1)
#define TWL6030_GPADCR                          BIT(0)

/**
 * struct twl6030_chnl_calib - channel calibration
 * @gain:               slope coefficient for ideal curve
 * @gain_error:         gain error
 * @offset_error:       offset of the real curve
 */
struct twl6030_chnl_calib {
        s32 gain;
        s32 gain_error;
        s32 offset_error;
};

/**
 * struct twl6030_ideal_code - GPADC calibration parameters
 * GPADC is calibrated in two points: close to the beginning and
 * to the and of the measurable input range
 *
 * @channel:    channel number
 * @code1:      ideal code for the input at the beginning
 * @code2:      ideal code for at the end of the range
 * @volt1:      voltage input at the beginning(low voltage)
 * @volt2:      voltage input at the end(high voltage)
 */
struct twl6030_ideal_code {
        int channel;
        u16 code1;
        u16 code2;
        u16 volt1;
        u16 volt2;
};

struct twl6030_gpadc_data;

/**
 * struct twl6030_gpadc_platform_data - platform specific data
 * @nchannels:          number of GPADC channels
 * @iio_channels:       iio channels
 * @twl6030_ideal:      pointer to calibration parameters
 * @start_conversion:   pointer to ADC start conversion function
 * @channel_to_reg      pointer to ADC function to convert channel to
 *                      register address for reading conversion result
 * @calibrate:          pointer to calibration function
 */
struct twl6030_gpadc_platform_data {
        const int nchannels;
        const struct iio_chan_spec *iio_channels;
        const struct twl6030_ideal_code *ideal;
        int (*start_conversion)(int channel);
        u8 (*channel_to_reg)(int channel);
        int (*calibrate)(struct twl6030_gpadc_data *gpadc);
};

/**
 * struct twl6030_gpadc_data - GPADC data
 * @dev:                device pointer
 * @lock:               mutual exclusion lock for the structure
 * @irq_complete:       completion to signal end of conversion
 * @twl6030_cal_tbl:    pointer to calibration data for each
 *                      channel with gain error and offset
 * @pdata:              pointer to device specific data
 */
struct twl6030_gpadc_data {
        struct device   *dev;
        struct mutex    lock;
        struct completion       irq_complete;
        struct twl6030_chnl_calib       *twl6030_cal_tbl;
        const struct twl6030_gpadc_platform_data *pdata;
};

/*
 * channels 11, 12, 13, 15 and 16 have no calibration data
 * calibration offset is same for channels 1, 3, 4, 5
 *
 * The data is taken from GPADC_TRIM registers description.
 * GPADC_TRIM registers keep difference between the code measured
 * at volt1 and volt2 input voltages and corresponding code1 and code2
 */
static const struct twl6030_ideal_code
        twl6030_ideal[TWL6030_GPADC_USED_CHANNELS] = {
        [0] = { /* ch 0, external, battery type, resistor value */
                .channel = 0,
                .code1 = 116,
                .code2 = 745,
                .volt1 = 141,
                .volt2 = 910,
        },
        [1] = { /* ch 1, external, battery temperature, NTC resistor value */
                .channel = 1,
                .code1 = 82,
                .code2 = 900,
                .volt1 = 100,
                .volt2 = 1100,
        },
        [2] = { /* ch 2, external, audio accessory/general purpose */
                .channel = 2,
                .code1 = 55,
                .code2 = 818,
                .volt1 = 101,
                .volt2 = 1499,
        },
        [3] = { /* ch 3, external, general purpose */
                .channel = 3,
                .code1 = 82,
                .code2 = 900,
                .volt1 = 100,
                .volt2 = 1100,
        },
        [4] = { /* ch 4, external, temperature measurement/general purpose */
                .channel = 4,
                .code1 = 82,
                .code2 = 900,
                .volt1 = 100,
                .volt2 = 1100,
        },
        [5] = { /* ch 5, external, general purpose */
                .channel = 5,
                .code1 = 82,
                .code2 = 900,
                .volt1 = 100,
                .volt2 = 1100,
        },
        [6] = { /* ch 6, external, general purpose */
                .channel = 6,
                .code1 = 82,
                .code2 = 900,
                .volt1 = 100,
                .volt2 = 1100,
        },
        [7] = { /* ch 7, internal, main battery */
                .channel = 7,
                .code1 = 614,
                .code2 = 941,
                .volt1 = 3001,
                .volt2 = 4599,
        },
        [8] = { /* ch 8, internal, backup battery */
                .channel = 8,
                .code1 = 82,
                .code2 = 688,
                .volt1 = 501,
                .volt2 = 4203,
        },
        [9] = { /* ch 9, internal, external charger input */
                .channel = 9,
                .code1 = 182,
                .code2 = 818,
                .volt1 = 2001,
                .volt2 = 8996,
        },
        [10] = { /* ch 10, internal, VBUS */
                .channel = 10,
                .code1 = 149,
                .code2 = 818,
                .volt1 = 1001,
                .volt2 = 5497,
        },
        [11] = { /* ch 11, internal, VBUS charging current */
                .channel = 11,
        },
                /* ch 12, internal, Die temperature */
                /* ch 13, internal, Die temperature */
        [12] = { /* ch 14, internal, USB ID line */
                .channel = 14,
                .code1 = 48,
                .code2 = 714,
                .volt1 = 323,
                .volt2 = 4800,
        },
};

static const struct twl6030_ideal_code
                        twl6032_ideal[TWL6032_GPADC_USED_CHANNELS] = {
        [0] = { /* ch 0, external, battery type, resistor value */
                .channel = 0,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 440,
                .volt2 = 1000,
        },
        [1] = { /* ch 1, external, battery temperature, NTC resistor value */
                .channel = 1,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 440,
                .volt2 = 1000,
        },
        [2] = { /* ch 2, external, audio accessory/general purpose */
                .channel = 2,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 660,
                .volt2 = 1500,
        },
        [3] = { /* ch 3, external, temperature with external diode/general
                                                                purpose */
                .channel = 3,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 440,
                .volt2 = 1000,
        },
        [4] = { /* ch 4, external, temperature measurement/general purpose */
                .channel = 4,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 440,
                .volt2 = 1000,
        },
        [5] = { /* ch 5, external, general purpose */
                .channel = 5,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 440,
                .volt2 = 1000,
        },
        [6] = { /* ch 6, external, general purpose */
                .channel = 6,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 440,
                .volt2 = 1000,
        },
        [7] = { /* ch7, internal, system supply */
                .channel = 7,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 2200,
                .volt2 = 5000,
        },
        [8] = { /* ch8, internal, backup battery */
                .channel = 8,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 2200,
                .volt2 = 5000,
        },
        [9] = { /* ch 9, internal, external charger input */
                .channel = 9,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 3960,
                .volt2 = 9000,
        },
        [10] = { /* ch10, internal, VBUS */
                .channel = 10,
                .code1 = 150,
                .code2 = 751,
                .volt1 = 1000,
                .volt2 = 5000,
        },
        [11] = { /* ch 11, internal, VBUS DC-DC output current */
                .channel = 11,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 660,
                .volt2 = 1500,
        },
                /* ch 12, internal, Die temperature */
                /* ch 13, internal, Die temperature */
        [12] = { /* ch 14, internal, USB ID line */
                .channel = 14,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 2420,
                .volt2 = 5500,
        },
                /* ch 15, internal, test network */
                /* ch 16, internal, test network */
        [13] = { /* ch 17, internal, battery charging current */
                .channel = 17,
        },
        [14] = { /* ch 18, internal, battery voltage */
                .channel = 18,
                .code1 = 1441,
                .code2 = 3276,
                .volt1 = 2200,
                .volt2 = 5000,
        },
};

static inline int twl6030_gpadc_write(u8 reg, u8 val)
{
        return twl_i2c_write_u8(TWL6030_MODULE_GPADC, val, reg);
}

static inline int twl6030_gpadc_read(u8 reg, u8 *val)
{

        return twl_i2c_read(TWL6030_MODULE_GPADC, val, reg, 2);
}

static int twl6030_gpadc_enable_irq(u8 mask)
{
        int ret;

        ret = twl6030_interrupt_unmask(mask, REG_INT_MSK_LINE_B);
        if (ret < 0)
                return ret;

        ret = twl6030_interrupt_unmask(mask, REG_INT_MSK_STS_B);

        return ret;
}

static void twl6030_gpadc_disable_irq(u8 mask)
{
        twl6030_interrupt_mask(mask, REG_INT_MSK_LINE_B);
        twl6030_interrupt_mask(mask, REG_INT_MSK_STS_B);
}

static irqreturn_t twl6030_gpadc_irq_handler(int irq, void *indio_dev)
{
        struct twl6030_gpadc_data *gpadc = iio_priv(indio_dev);

        complete(&gpadc->irq_complete);

        return IRQ_HANDLED;
}

static int twl6030_start_conversion(int channel)
{
        return twl6030_gpadc_write(TWL6030_GPADC_CTRL_P1,
                                        TWL6030_GPADC_CTRL_P1_SP1);
}

static int twl6032_start_conversion(int channel)
{
        int ret;

        ret = twl6030_gpadc_write(TWL6032_GPADC_GPSELECT_ISB, channel);
        if (ret)
                return ret;

        return twl6030_gpadc_write(TWL6032_GPADC_CTRL_P1,
                                                TWL6030_GPADC_CTRL_P1_SP1);
}

static u8 twl6030_channel_to_reg(int channel)
{
        return TWL6030_GPADC_GPCH0_LSB + 2 * channel;
}

static u8 twl6032_channel_to_reg(int channel)
{
        /*
         * for any prior chosen channel, when the conversion is ready
         * the result is avalable in GPCH0_LSB, GPCH0_MSB.
         */

        return TWL6032_GPADC_GPCH0_LSB;
}

static int twl6030_gpadc_lookup(const struct twl6030_ideal_code *ideal,
                int channel, int size)
{
        int i;

        for (i = 0; i < size; i++)
                if (ideal[i].channel == channel)
                        break;

        return i;
}

static int twl6030_channel_calibrated(const struct twl6030_gpadc_platform_data
                *pdata, int channel)
{
        const struct twl6030_ideal_code *ideal = pdata->ideal;
        int i;

        i = twl6030_gpadc_lookup(ideal, channel, pdata->nchannels);
        /* not calibrated channels have 0 in all structure members */
        return pdata->ideal[i].code2;
}

static int twl6030_gpadc_make_correction(struct twl6030_gpadc_data *gpadc,
                int channel, int raw_code)
{
        const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;
        int corrected_code;
        int i;

        i = twl6030_gpadc_lookup(ideal, channel, gpadc->pdata->nchannels);
        corrected_code = ((raw_code * 1000) -
                gpadc->twl6030_cal_tbl[i].offset_error) /
                gpadc->twl6030_cal_tbl[i].gain_error;

        return corrected_code;
}

static int twl6030_gpadc_get_raw(struct twl6030_gpadc_data *gpadc,
                int channel, int *res)
{
        u8 reg = gpadc->pdata->channel_to_reg(channel);
        __le16 val;
        int raw_code;
        int ret;

        ret = twl6030_gpadc_read(reg, (u8 *)&val);
        if (ret) {
                dev_dbg(gpadc->dev, "unable to read register 0x%X\n", reg);
                return ret;
        }

        raw_code = le16_to_cpu(val);
        dev_dbg(gpadc->dev, "GPADC raw code: %d", raw_code);

        if (twl6030_channel_calibrated(gpadc->pdata, channel))
                *res = twl6030_gpadc_make_correction(gpadc, channel, raw_code);
        else
                *res = raw_code;

        return ret;
}

static int twl6030_gpadc_get_processed(struct twl6030_gpadc_data *gpadc,
                int channel, int *val)
{
        const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;
        int corrected_code;
        int channel_value;
        int i;
        int ret;

        ret = twl6030_gpadc_get_raw(gpadc, channel, &corrected_code);
        if (ret)
                return ret;

        i = twl6030_gpadc_lookup(ideal, channel, gpadc->pdata->nchannels);
        channel_value = corrected_code *
                        gpadc->twl6030_cal_tbl[i].gain;

        /* Shift back into mV range */
        channel_value /= 1000;

        dev_dbg(gpadc->dev, "GPADC corrected code: %d", corrected_code);
        dev_dbg(gpadc->dev, "GPADC value: %d", channel_value);

        *val = channel_value;

        return ret;
}

static int twl6030_gpadc_read_raw(struct iio_dev *indio_dev,
                             const struct iio_chan_spec *chan,
                             int *val, int *val2, long mask)
{
        struct twl6030_gpadc_data *gpadc = iio_priv(indio_dev);
        int ret;
        long timeout;

        mutex_lock(&gpadc->lock);

        ret = gpadc->pdata->start_conversion(chan->channel);
        if (ret) {
                dev_err(gpadc->dev, "failed to start conversion\n");
                goto err;
        }
        /* wait for conversion to complete */
        timeout = wait_for_completion_interruptible_timeout(
                                &gpadc->irq_complete, msecs_to_jiffies(5000));
        if (timeout == 0) {
                ret = -ETIMEDOUT;
                goto err;
        } else if (timeout < 0) {
                ret = -EINTR;
                goto err;
        }

        switch (mask) {
        case IIO_CHAN_INFO_RAW:
                ret = twl6030_gpadc_get_raw(gpadc, chan->channel, val);
                ret = ret ? -EIO : IIO_VAL_INT;
                break;

        case IIO_CHAN_INFO_PROCESSED:
                ret = twl6030_gpadc_get_processed(gpadc, chan->channel, val);
                ret = ret ? -EIO : IIO_VAL_INT;
                break;

        default:
                break;
        }
err:
        mutex_unlock(&gpadc->lock);

        return ret;
}

/*
 * The GPADC channels are calibrated using a two point calibration method.
 * The channels measured with two known values: volt1 and volt2, and
 * ideal corresponding output codes are known: code1, code2.
 * The difference(d1, d2) between ideal and measured codes stored in trim
 * registers.
 * The goal is to find offset and gain of the real curve for each calibrated
 * channel.
 * gain: k = 1 + ((d2 - d1) / (x2 - x1))
 * offset: b = d1 + (k - 1) * x1
 */
static void twl6030_calibrate_channel(struct twl6030_gpadc_data *gpadc,
                int channel, int d1, int d2)
{
        int b, k, gain, x1, x2, i;
        const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;

        i = twl6030_gpadc_lookup(ideal, channel, gpadc->pdata->nchannels);

        /* Gain */
        gain = ((ideal[i].volt2 - ideal[i].volt1) * 1000) /
                (ideal[i].code2 - ideal[i].code1);

        x1 = ideal[i].code1;
        x2 = ideal[i].code2;

        /* k - real curve gain */
        k = 1000 + (((d2 - d1) * 1000) / (x2 - x1));

        /* b - offset of the real curve gain */
        b = (d1 * 1000) - (k - 1000) * x1;

        gpadc->twl6030_cal_tbl[i].gain = gain;
        gpadc->twl6030_cal_tbl[i].gain_error = k;
        gpadc->twl6030_cal_tbl[i].offset_error = b;

        dev_dbg(gpadc->dev, "GPADC d1   for Chn: %d = %d\n", channel, d1);
        dev_dbg(gpadc->dev, "GPADC d2   for Chn: %d = %d\n", channel, d2);
        dev_dbg(gpadc->dev, "GPADC x1   for Chn: %d = %d\n", channel, x1);
        dev_dbg(gpadc->dev, "GPADC x2   for Chn: %d = %d\n", channel, x2);
        dev_dbg(gpadc->dev, "GPADC Gain for Chn: %d = %d\n", channel, gain);
        dev_dbg(gpadc->dev, "GPADC k    for Chn: %d = %d\n", channel, k);
        dev_dbg(gpadc->dev, "GPADC b    for Chn: %d = %d\n", channel, b);
}

static inline int twl6030_gpadc_get_trim_offset(s8 d)
{
        /*
         * XXX NOTE!
         * bit 0 - sign, bit 7 - reserved, 6..1 - trim value
         * though, the documentation states that trim value
         * is absolute value, the correct conversion results are
         * obtained if the value is interpreted as 2's complement.
         */
        __u32 temp = ((d & 0x7f) >> 1) | ((d & 1) << 6);

        return sign_extend32(temp, 6);
}

static int twl6030_calibration(struct twl6030_gpadc_data *gpadc)
{
        int ret;
        int chn;
        u8 trim_regs[TWL6030_GPADC_NUM_TRIM_REGS];
        s8 d1, d2;

        /*
         * for calibration two measurements have been performed at
         * factory, for some channels, during the production test and
         * have been stored in registers. This two stored values are
         * used to correct the measurements. The values represent
         * offsets for the given input from the output on ideal curve.
         */
        ret = twl_i2c_read(TWL6030_MODULE_ID2, trim_regs,
                        TWL6030_GPADC_TRIM1, TWL6030_GPADC_NUM_TRIM_REGS);
        if (ret < 0) {
                dev_err(gpadc->dev, "calibration failed\n");
                return ret;
        }

        for (chn = 0; chn < TWL6030_GPADC_MAX_CHANNELS; chn++) {

                switch (chn) {
                case 0:
                        d1 = trim_regs[0];
                        d2 = trim_regs[1];
                        break;
                case 1:
                case 3:
                case 4:
                case 5:
                case 6:
                        d1 = trim_regs[4];
                        d2 = trim_regs[5];
                        break;
                case 2:
                        d1 = trim_regs[12];
                        d2 = trim_regs[13];
                        break;
                case 7:
                        d1 = trim_regs[6];
                        d2 = trim_regs[7];
                        break;
                case 8:
                        d1 = trim_regs[2];
                        d2 = trim_regs[3];
                        break;
                case 9:
                        d1 = trim_regs[8];
                        d2 = trim_regs[9];
                        break;
                case 10:
                        d1 = trim_regs[10];
                        d2 = trim_regs[11];
                        break;
                case 14:
                        d1 = trim_regs[14];
                        d2 = trim_regs[15];
                        break;
                default:
                        continue;
                }

                d1 = twl6030_gpadc_get_trim_offset(d1);
                d2 = twl6030_gpadc_get_trim_offset(d2);

                twl6030_calibrate_channel(gpadc, chn, d1, d2);
        }

        return 0;
}

static int twl6032_get_trim_value(u8 *trim_regs, unsigned int reg0,
                unsigned int reg1, unsigned int mask0, unsigned int mask1,
                unsigned int shift0)
{
        int val;

        val = (trim_regs[reg0] & mask0) << shift0;
        val |= (trim_regs[reg1] & mask1) >> 1;
        if (trim_regs[reg1] & 0x01)
                val = -val;

        return val;
}

static int twl6032_calibration(struct twl6030_gpadc_data *gpadc)
{
        int chn, d1 = 0, d2 = 0, temp;
        u8 trim_regs[TWL6030_GPADC_NUM_TRIM_REGS];
        int ret;

        ret = twl_i2c_read(TWL6030_MODULE_ID2, trim_regs,
                        TWL6030_GPADC_TRIM1, TWL6030_GPADC_NUM_TRIM_REGS);
        if (ret < 0) {
                dev_err(gpadc->dev, "calibration failed\n");
                return ret;
        }

        /*
         * Loop to calculate the value needed for returning voltages from
         * GPADC not values.
         *
         * gain is calculated to 3 decimal places fixed point.
         */
        for (chn = 0; chn < TWL6032_GPADC_MAX_CHANNELS; chn++) {

                switch (chn) {
                case 0:
                case 1:
                case 2:
                case 3:
                case 4:
                case 5:
                case 6:
                case 11:
                case 14:
                        d1 = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
                                                                0x06, 2);
                        d2 = twl6032_get_trim_value(trim_regs, 3, 1, 0x3f,
                                                                0x06, 2);
                        break;
                case 8:
                        temp = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
                                                                0x06, 2);
                        d1 = temp + twl6032_get_trim_value(trim_regs, 7, 6,
                                                                0x18, 0x1E, 1);

                        temp = twl6032_get_trim_value(trim_regs, 3, 1, 0x3F,
                                                                0x06, 2);
                        d2 = temp + twl6032_get_trim_value(trim_regs, 9, 7,
                                                                0x1F, 0x06, 2);
                        break;
                case 9:
                        temp = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
                                                                0x06, 2);
                        d1 = temp + twl6032_get_trim_value(trim_regs, 13, 11,
                                                                0x18, 0x1E, 1);

                        temp = twl6032_get_trim_value(trim_regs, 3, 1, 0x3f,
                                                                0x06, 2);
                        d2 = temp + twl6032_get_trim_value(trim_regs, 15, 13,
                                                                0x1F, 0x06, 1);
                        break;
                case 10:
                        d1 = twl6032_get_trim_value(trim_regs, 10, 8, 0x0f,
                                                                0x0E, 3);
                        d2 = twl6032_get_trim_value(trim_regs, 14, 12, 0x0f,
                                                                0x0E, 3);
                        break;
                case 7:
                case 18:
                        temp = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
                                                                0x06, 2);

                        d1 = (trim_regs[4] & 0x7E) >> 1;
                        if (trim_regs[4] & 0x01)
                                d1 = -d1;
                        d1 += temp;

                        temp = twl6032_get_trim_value(trim_regs, 3, 1, 0x3f,
                                                                0x06, 2);

                        d2 = (trim_regs[5] & 0xFE) >> 1;
                        if (trim_regs[5] & 0x01)
                                d2 = -d2;

                        d2 += temp;
                        break;
                default:
                        /* No data for other channels */
                        continue;
                }

                twl6030_calibrate_channel(gpadc, chn, d1, d2);
        }

        return 0;
}

#define TWL6030_GPADC_CHAN(chn, _type, chan_info) {     \
        .type = _type,                                  \
        .channel = chn,                                 \
        .info_mask_separate = BIT(chan_info),           \
        .indexed = 1,                                   \
}

static const struct iio_chan_spec twl6030_gpadc_iio_channels[] = {
        TWL6030_GPADC_CHAN(0, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(1, IIO_TEMP, IIO_CHAN_INFO_RAW),
        TWL6030_GPADC_CHAN(2, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(3, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(4, IIO_TEMP, IIO_CHAN_INFO_RAW),
        TWL6030_GPADC_CHAN(5, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(6, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(7, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(8, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(9, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(10, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(11, IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
        TWL6030_GPADC_CHAN(14, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
};

static const struct iio_chan_spec twl6032_gpadc_iio_channels[] = {
        TWL6030_GPADC_CHAN(0, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(1, IIO_TEMP, IIO_CHAN_INFO_RAW),
        TWL6030_GPADC_CHAN(2, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(3, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(4, IIO_TEMP, IIO_CHAN_INFO_RAW),
        TWL6030_GPADC_CHAN(5, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(6, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(7, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(8, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(9, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(10, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(11, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(14, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
        TWL6030_GPADC_CHAN(17, IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
        TWL6030_GPADC_CHAN(18, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
};

static const struct iio_info twl6030_gpadc_iio_info = {
        .read_raw = &twl6030_gpadc_read_raw,
        .driver_module = THIS_MODULE,
};

static const struct twl6030_gpadc_platform_data twl6030_pdata = {
        .iio_channels = twl6030_gpadc_iio_channels,
        .nchannels = TWL6030_GPADC_USED_CHANNELS,
        .ideal = twl6030_ideal,
        .start_conversion = twl6030_start_conversion,
        .channel_to_reg = twl6030_channel_to_reg,
        .calibrate = twl6030_calibration,
};

static const struct twl6030_gpadc_platform_data twl6032_pdata = {
        .iio_channels = twl6032_gpadc_iio_channels,
        .nchannels = TWL6032_GPADC_USED_CHANNELS,
        .ideal = twl6032_ideal,
        .start_conversion = twl6032_start_conversion,
        .channel_to_reg = twl6032_channel_to_reg,
        .calibrate = twl6032_calibration,
};

static const struct of_device_id of_twl6030_match_tbl[] = {
        {
                .compatible = "ti,twl6030-gpadc",
                .data = &twl6030_pdata,
        },
        {
                .compatible = "ti,twl6032-gpadc",
                .data = &twl6032_pdata,
        },
        { /* end */ }
};
MODULE_DEVICE_TABLE(of, of_twl6030_match_tbl);

static int twl6030_gpadc_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct twl6030_gpadc_data *gpadc;
        const struct twl6030_gpadc_platform_data *pdata;
        const struct of_device_id *match;
        struct iio_dev *indio_dev;
        int irq;
        int ret;

        match = of_match_device(of_twl6030_match_tbl, dev);
        if (!match)
                return -EINVAL;

        pdata = match->data;

        indio_dev = devm_iio_device_alloc(dev, sizeof(*gpadc));
        if (!indio_dev)
                return -ENOMEM;

        gpadc = iio_priv(indio_dev);

        gpadc->twl6030_cal_tbl = devm_kzalloc(dev,
                                        sizeof(*gpadc->twl6030_cal_tbl) *
                                        pdata->nchannels, GFP_KERNEL);
        if (!gpadc->twl6030_cal_tbl)
                return -ENOMEM;

        gpadc->dev = dev;
        gpadc->pdata = pdata;

        platform_set_drvdata(pdev, indio_dev);
        mutex_init(&gpadc->lock);
        init_completion(&gpadc->irq_complete);

        ret = pdata->calibrate(gpadc);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to read calibration registers\n");
                return ret;
        }

        irq = platform_get_irq(pdev, 0);
        if (irq < 0) {
                dev_err(&pdev->dev, "failed to get irq\n");
                return irq;
        }

        ret = devm_request_threaded_irq(dev, irq, NULL,
                                twl6030_gpadc_irq_handler,
                                IRQF_ONESHOT, "twl6030_gpadc", indio_dev);

        ret = twl6030_gpadc_enable_irq(TWL6030_GPADC_RT_SW1_EOC_MASK);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to enable GPADC interrupt\n");
                return ret;
        }

        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCS,
                                        TWL6030_REG_TOGGLE1);
        if (ret < 0) {
                dev_err(&pdev->dev, "failed to enable GPADC module\n");
                return ret;
        }

        indio_dev->name = DRIVER_NAME;
        indio_dev->dev.parent = dev;
        indio_dev->info = &twl6030_gpadc_iio_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = pdata->iio_channels;
        indio_dev->num_channels = pdata->nchannels;

        return iio_device_register(indio_dev);
}

static int twl6030_gpadc_remove(struct platform_device *pdev)
{
        struct iio_dev *indio_dev = platform_get_drvdata(pdev);

        twl6030_gpadc_disable_irq(TWL6030_GPADC_RT_SW1_EOC_MASK);
        iio_device_unregister(indio_dev);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int twl6030_gpadc_suspend(struct device *pdev)
{
        int ret;

        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCR,
                                TWL6030_REG_TOGGLE1);
        if (ret)
                dev_err(pdev, "error resetting GPADC (%d)!\n", ret);

        return 0;
};

static int twl6030_gpadc_resume(struct device *pdev)
{
        int ret;

        ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCS,
                                TWL6030_REG_TOGGLE1);
        if (ret)
                dev_err(pdev, "error setting GPADC (%d)!\n", ret);

        return 0;
};
#endif

static SIMPLE_DEV_PM_OPS(twl6030_gpadc_pm_ops, twl6030_gpadc_suspend,
                                        twl6030_gpadc_resume);

static struct platform_driver twl6030_gpadc_driver = {
        .probe          = twl6030_gpadc_probe,
        .remove         = twl6030_gpadc_remove,
        .driver         = {
                .name   = DRIVER_NAME,
                .pm     = &twl6030_gpadc_pm_ops,
                .of_match_table = of_twl6030_match_tbl,
        },

};

module_platform_driver(twl6030_gpadc_driver);

MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_AUTHOR("Balaji T K <balajitk@ti.com>");
MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
MODULE_AUTHOR("Oleksandr Kozaruk <oleksandr.kozaruk@ti.com");
MODULE_DESCRIPTION("twl6030 ADC driver");
MODULE_LICENSE("GPL");